Trench-digging machine



July 16, 1929.

R. BROWN TRENCH DIGGING MACHINE 2 Sheets-Sheet l [.VVENTOR.

fioberf L. Brow/z A TTORNEY)- Filgd April 9, 1926 July 16, 1929. R. BROWN I TRENCH DIGGING MACHINE Filed April 9, 1926 2 sheets-sheet 2 v INVENTOR.

By Robe/ f L. Brown I ATTORNEYS Patented July 16, 1929.

ROBERT L. BROWN, or MILWAUKEE, isconsin, Assmno 'ro HARNIS' III GER. CORPORATION, or MILWAUKEE, wIscoNsIN, aconroRA'rIoN or WISCONSIN.

TRENCI-I-DIGGING MACHINE. 1

Application filed April 9, 1926. Serial- No.100,783.

This invention relates to improvements in trench or ditch digging machines of the socalled ladder type, and more particularly to an improved crowding and hoisting mechanism for the boom and excavating buckets carried thereby.

Machines of the character referred to comprise, in general, a frame mounted on wheels at the front end thereof and onja suitable tractor at the rear end of the same, a rearwardly extending boom pivotally connected to the frame and carrying rollers on which endless chains with buckets attached run, and suitable mechanism mounted on the is not sufficient to hold the same down and the excavating buckets in proper cutting position, the action of the boom being to rebound away from the bank upon engage-v ment of the buckets with the obstruction.

One of the objects .of the present invention, therefore, is to provide improved means providing for a crowding action for the boom and excavating buckets carried thereby, whereby the latter are held in proper cutting position with respect to the bank, and wherein the boom is permitted to.

yield. or rebound somewhat should the buckets strike an obstruction such: as a boulder format1on,'serv1ce pipe, or the like. Another ob ect 15 to provide, In a machine of the character referred to, improved means for hoisting or adjusting the boom so that the tension or strain in the boom supporting cables on either side of the boom is equalized.

Another object is to provide, in a machine of the character referred to, improved means for providing for a crowding-action for the boom and wherein such means may be readily disconnected if desired to permit the boom to rebound freely, or for any other reason.

Another object is to provide, in a machine of. the character. referred to, improved crowding and hoisting mechanism for the boom having advantages over such mechanism constructed heretofore I as regards simplicity of construction and manner of operation. 1

Other objects and advantages will herein; I d

after appear.

For the purpose of'illustrating the invention an embodiment thereof is shown in the drawings, in which:

F'gure 1 is a side elevational view of the type, showing the improved crowding and hoisting mechanism operatively associated therewith, the endless belt traction'element being shown merely in dotted lines in order to better illustrate the crowding device.-.

. Fig. 2 is anend elevation, looking toward the left in Fig. 1, some of the parts being removed rear end of a trench machine of the ladder Fig. 3 is aplan view of Fig. 1, some of the v parts being removed;'

Fig. l is an en'larged'plan view of some of the parts comprising the crowding mech- 5 is a front elevational view of Fig. 4'; i Fig. 6 is a fragmentary plan view ofthe bolaster forming part of the tractor frame; an I Fig. 7 an elevational view, looking toward the left in Fig. 6. p

The frame of the machine, designated generally by the reference numeral 1, is sup} ported at its reare'nd by means of a suitable tractor 2 having a bolster 3 provided at oneend with spaced lugs 4 and a downwardly extending lug 5, the respective ends of the-bolster receiving and supporting the usual stub shafts 6 forf driving and supporting the endless traction belts 7 and 8. A-

with-groovedhoist-drums 10 and 11 and with grooved crowding drums, 12 and 13 fixed to this shaft for rotation therewith; A pair of sheaves lland 14 and. a'second pair of shaft 9 is supported by and journaled in any] suitable manner in frame 1 and is provided;

sheaves 15 and 151are loosely fitted "on a shaft-16 supported by framel and arranged A brackets 19. Sheaves 2l-are arranged on either side of boom 20, as more clearly shown in Fig. 2, and are supported by means .of

brackets 22 for rotation about axes transverse to shaft 19 or in other words, transverse to the aXesof rotation of sheaves 17 17, 18 and 18 mounted on shaft 19,brackets 22 being suspended from the frame member 23 through which shaft 16' extends.

Shaft 9 is driven or operated in either direction by means of a-reversible driveshaft 24 connected to shaft 9 by means of a sprocket chain-25 and sprocketwheels 26 and 27 fixed to theseshafts, as more'clearly shown in Figs. 1 and 3. Asingle cable 28 is anchored at oneend to drum 10 and extends over sheave 14, downwardly and around sheave 17,up

' wardly :and over sheaves 21, thence downwardly-and around sheave 17, and thence upwardly and over sheave 14, cable 28 then extending to drum'll and being anchored thereto. From the foregoing-it will beseen that upon operation of shaft 9 in aicounterclockwise direction, as viewed in Fig. 1, the ends of" cable 28 will be wound upon drums 10:and 11 to causeraising or. upward movement of boom 20' and its associated parts about shaft 29, by meansof which latter shaft theboom ispivotally connected to frame 1,'and that upon-reverse operation or rotation of shaft 9-the boom will belowered. The use of sheaves 21 and the manner in which they are arranged permit of the use of a single cable for raising and lowering the boom, this providing for equalized suspension of the boom on either side thereof. v

A sheave 30, mounted in a suitable housing 31, is arranged on one side of the machine as shown and is pivotallyconnected to lugs 4 by means ofa pin 32. Abolt 33 extends longitudinally of the machine and loosely through lug 5, and ispivotallyconnect-ed to housing 31 by means of a pin 34, a; coiled spring-35 being arranged on the boltbetween h1g5 and nuts 36threaded on the end of the bolt.

-A cable 37 is fixed atone end-to drum-12 andextends oversheave 15 and downwardly and around sheave 30, and thence around sheave 18 and back toward sheave 30, cable 37 at this point being pivotally connected to housing 31 by any suitable means such as the U-shaped strap 38 having its ends loosely fitting'over theextended ends of shaft 39 ex tending through-housing 31 and upon which sheave30 rotates. v i

A second cable'AO is fixed at one end'to drum 13- and extends over sheave 15"and downwardly and around a sheave 30 similar to and supported in the same manner as sheave 30, and thence around sheave 1-8 and back toward sheave 30, the cable being secured at this point to the, shaft of sheave 30f in the same manner as-tlie corresponding end of cable 37 is secured to shaft 39 of sheave As more clearly shown m-Fig. 1 the ar rangement is such that upon rotation of shaft 9 in a counter-clockwise direction, the ends of the single cable 28 W11]. be wound up a certain amount on the hoisting drums 10 and 11 to cause raising of the boom, while the cables 37 and 40 will be unwound or payed out this same amount from the crowing drums 12 and 13 so that the boom and its associated parts are permitted to be raised by means of cable 28. Upon reverse rotation of shaft 9,

the endsof the singlecable 28 are unwound orpayed out fromthe hoisting drums 10 and 11 to permit the boom and its associated parts away from the bank by cables 37 and 40 and cooperating parts. The boom is thus adjust-- ed according to the depth of the trench or Y ditch to the dug, and shaft 9 held in any suitable manner against movement in either direction until the .neXt adjustment :is to be made. In the eventthat one of the buckets 11 strikes an obstruction such as a boulder or 1 service pipe, the boom will rebound away from the bank, w th a corresponding increase in thetension of cables 37 and 40, thisbeing accompanied by pivotal movement of th sheave houslng 31 about pins 32 and further compressionof springs 35 between lugs Sand the stops or nuts 36. Springs 35 thus provide for a yieldable crowding action on the boom wherebythe latter is permitted to give or rebound to some extent when the buckets encounter an extraordinary obstruction, the springs acting to return the boom to its normalrposition' after the obstruction has been I passed.

sion in springs 35, caused by their compres sion between lugs 5 and nuts 36, maintain such tension in cables 37 and 40 that the boom and buckets carried thereby are crowded or held into the bank with suflicient force to provide for proper cutting action underconditions usually encountered. To meet varying conditions, such as for instance where the ground is very hard, nuts 36 may be adjusted on bolts33 to cause greater initial compression of springs 35 and corresponding greater tension in cables 37 and 40 and greater crowding action on the boom and buckets. Adjustment of nuts 36 towardthe ends of bolts 33 will, of course, produce the'opposite effect, and result in less crowding action on the boom and buckets. v Such anadjustinent may be advantageous in working in comparatively soft or loose dirt. .f it is desired'to During operation of the machine, the teneliminate the crowding action of springs 35 and the associated parts, cables37- andlO may be disconnected by removing pins 4:2 orby disconnecting the ends of these cables from thecrowding drums -12 and=13. 7

From the foregoing it will be seen that improved hoisting and crowding mechanism for trenching machines of tl1e ladde1""type has been provided which is'simple in construction and mannerof operation, and which may be ad usted to meet varylng'conditions,

lVhile oneembodiment of the invention has been shown and described, it is to be underwinding thereabout upon rotation of the, same in a given direc-tlon to effect raislng of said boom, and a second cable operatively connected to said boom and extending clownwardly therefrom' and connected to said shaft for winding thereabout upon rotation I ofthe same in the opposite direction to urge said boom downwardly toward the work.

2 In a machine of the character described, the combination with the framev and boom thereof, and an "operating shaft mountedon said frame,of a first cable operatively con? nected to said boom and extendingupwardly therefrom and connectedto saidshaftfbr winding thereabout upon rotation of the same in a given direction to effect raising of said boom, a second cable operatively connected 7 to said "boom and extending downwardly therefrom and connected to said shaft for windingthereabout 'upon rotation of the same in the opposite direction to urge. said boom downwardly toward the work,--and yielding means operatively associated with sa1dsecond cable.'-

3. In a machine of the character described,"

the combination with the frame and ,boom

' thereof, of an operating shaft mountedon saidframe, aplurality of drums fixed on.- said shaft, a first cable operatively connected to said boom and extending'upwardly :there-' from. and being fixed at one end toone of said drums for winding thereon upon rotation of said shaft in one direction to-efi'ect raising ,of said boom, and asecond' cable operatively connected to said boom andextending downwardly therefrom and; being fixed at-one end to another of said drums for winding thereon upon rotation of said shaft in the opposite direction to urge said boom"- downwardly'tow'ardthe work. I

41-. Ina machine of the character described,

the combination- With the fr'ameand boom thereof, of airoperatingshaft mounted on said frame, a plurality'of drums fixed on said shaft, a first cable operatively. connected to said I boom and extending upwardly there? from and being fixed at' one end "to one of said drums for winding thereon upon'rotation ofsaid sh'aftin one direction to effect raising of sad boom, a second cable operatively connected tosaid boom and extending downwardly therefrom and being fixed at one end to another of said drums fojrwinding.

thereon upo'n rotationof said shaft in the opposite direction to urgesaid boom down wardly toward the work, and spring means operatively associated with said second'cable for yieldingly opposing upward movement of said boom away from the work.

' 5. In a machine of the character described,

the combination withthe' frame and boomthereof, of av-first and a second sheave cartried by said boom for rotation about a common axis, an operating shaft mounted on-said frame, a first cable trainedabout said first sheave and extending upwardly therefrom and being connected to said shaft for winding thereabout upon rotationof-the same in r a given direction toeffect raisingof said boom, and a second'c'able tralned about said second sheave and extending downwardly therefromand being connected to said shaft for winding thereabout upon rotation of the same in theoppositedirection to urge said boom downwardlytoward therwork.

6. In a' machine of the characterdescribed, the combination with theframe andboom thereof,*of :azfirst-and asecond sheave carriediby said boom for rotation about a-common axis, an operating shaft mounted-non said 'frameya first cable trained about said.

first sheave: and extending upwardly there- 7 from and'being connected tosaid' shaft for winding thereabout upon, rotation: of the same ina given direction to effectraising of said boom, a second cable trained about said second sheave and' extending downwardly therefrom and-being connected to said 1 shaft for winding thereabout upon rotation of the same in the opposite directionf to urge said boom downwardly toward the work, a third sheave associated with saidframe andsupported for pivotal movement with respect thereto and arranged below.saidsecond sheave, saidsecon'd cable beingtrained also about said third sheave, and spring means associated withsaid. third sheave and acting thereon to restrain said; movement of the latter'in one direction. I I p I 7. Ina machine of the character described, the combination with the frame and boom thereof, of a :member'associated with said frame and provided'withian apertured lug, a

housing pivotally connected to said member, a sheave arranged and our'nale'd'1n saidhousing, a bolt extending loosely through saidtlug and provided at one end with a'stop and connected at its other end to said housing, a

spring arranged on said bolt between said lugandsaid stop, anoperating shaft mountedon said frame, a cable operatively connected to said boom at apoint above-said sheave and being trained aboutlthe latter and connected to said shaft for winding thereabout upon rotation of the same in a given direction to urge said boom downwardly toward the work and'to cause compression ofsaid spring between said lug and said stop, and means for raising said boom. c

8. In a machine of the character-described,

the combination with the frame and boom thereof, of a member associated with said frame and provided with an a-pertured lug, a housing pivotally connected to said member, a sheavearranged and journaledin said housing, a bolt extending loosely through said lug and provided at one end with a stop and connected at its other end to said-housing,

a spring arranged on said bolt between said lug and said stop, an operating shaft mounted'on said frame, a cable operatively connected to saidboom at a point above said, sheave and being trained about the latter and connected to said shaft, for winding thereabout upon rotation ofv the same in a given directionto urge said boom downwardly toward the work and to cause compression of said spring between said lug and said stop, and means for raising said boom, said meansbeing connected to said shaft for operation thereby upon rotation of the same in the opposite direction.

9. In a machine of the character described, the combination with the frameand-boomv thereof, and an operating shaft mounted on said frame, of cable means operativelyconnected to said shaft and boom, a sheave engaging said cable means to cause the same to exert an upward pull on said boom upon op therefrom, said first and second cable means being connected to said shaftto effect pulling in on said first cable means to raise said boom and simultaneous paying out of said second cable means upon operation of said shaft in one direction and to effect pulling in on said second cable means to urge said boom toward the work and simultaneous paying out of said first cable means uponioperation of said shaft in the opposite direction.

11 In a machine of the. :charzicterdescribed, the combination with the frame and boom thereof, and adjusting means for said boom of a boltprovi-ded at one end thereof with a stopand extending longitudinally of said 'frame, means for guiding and support- 1ng said bolt, a drive shaft, cable means operativelyconnected to said shaft and said bolt andfsaid boom and extending down'-' ,wardly from the latter whereby thesame and itsassociated parts are moved toward the work upon operation of said shaft in one dibeing-said first-named means andsaid stop for yieldingly holding saidiboom in cutting position.

12. In a machine of .the character described, the combination with the frame and boomthereof, and adjusting means for said boom, of a sheave, means supporting "said sheave for pivotal movement with respect to said frame, a drum mountedon said frame,

rection, and a-spring arranged on said bolt a sheavecarried by said boom and arranged "above said first-named sheave, a flexible element fixed at one end to said drum and trained about said sheaves and fixed at its other end to said sheave-supporting means,

and means for operating said drum to wind up, said element thereon to effect crowding of saidboom and its associated parts toward the'work.

13. In a machine of the character described, the combination with the frame and boom thereof, and adjusting means for said boom, of a sheave, means supporting said sheave for pivotal movement with respect to said frame, a drum mountedon said frame, a sheave carried by said boom and arranged above said first-namedsheave a flexible element fixed at one end to said drum and trained about said'sheaves and fixed at its other end to said sheave-supporting means, means for operating said drum to windup said element thereon to effect crowding of said boom and its associated parts'toward the work, and a spring acting onsaid sheave-supporting means to restrain said pivotal movement thereof in one direction. I

14-11'1 a ladder type trenching machine, the combination with the boom thereof, of cable means for liftingcsaid boom, cable means for urging the" boom to its work, and means for simultaneously adplsting both sald cable means in such wise thatthetension of the'second-named cable means is maintained substantially constant for all positions of the boom; I I a r 15. Ina ladder type trenching machine, the combination'with the boom thereof, of cable meansfor lifting-said boom, cable means for urging the boom to its work, means for simultaneeusly adjusting both. said cable means such wise that the tension of the secondnamed cable means is maintained substantially constant for all positions of the boom, and a yielding connection interposed in said second-named cable means.

16. In a ladder type trenching machine, the combination with the boom thereof, of a yieldingly supported sheave mounted on said machine to the rear of said boom, a hoisting shaft, a plurality of cables associated therewith for reverse winding with respect thereto, one connected with the boom for raising the latter and the other passing over said sheave and connected with the boom for holding the latter to its work.

17. In a ladder type trenching machine,

the combination with the boom thereof, of-

a yieldingly supported sheave mounted on said machine to the rear of said boom, hoisting means, a cable for urging the boom to its work connected to said boom and passing rearwardly and over said sheave and then to the hoisting means, a cable for hoisting the boom connected to the latter and passing upwardly therefrom and to the hoisting means, said cables being arranged for relatively opposite travel upon operation of said hoisting means whereby the tension of said first-named cable is maintained substantially constant for all positions of the boom.

18. A ladder type trenchingmachine in cluding a boom, a flexible element operatively connected to the boom for positively lifting the same, a second and separate flexible element operatively connected with the boom for urging the boom toward its work, and a yieldablemeans associated with the second flexible element for permitting the boom to partake of limited movement away from its work when subjected to predetermined stresses. i

19. A ladder type trenching machine including a boom, a flexible element operatively connected to the boom for positively lifting I the same, a second and separate flexible element operatively connected with the boom for urging the boom toward its work, and a yieldable means associated with the second flexible element for permitting the boom to partake of limited movement away from its work when subjected to predetermined stresses, and means for simultaneously andreversely operating the flexible elements.

In witness whereof I hereto affix my signature.

ROBERT L. BROWN. 

